2,6-bis(1,1-dimethylethyl)-4-(phenylenemethylene)cyclohexa-2,5-dien-1-one

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to GLP and in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not effect the quality of the relevant results.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Substituted Quinone Methide

IUPAC Name:

Substituted Quinone Methide

Details on test material:

Storage: The test article was stored at room temperature and humidity.
Description: Yellow crystalline solid.

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Animals were received from Ace Animals, Boyertown, PA.
- Weight at study initiation: 2.2 - 2.5 kg
- Housing: 1 animap per cage in suspended wire cages. Bedding was placed beneath the cages and changed at least three times/week.
- Diet (e.g. ad libitum): Fresh Purina Rabbit Chow was provided daily.
- Water (e.g. ad libitum): Water was freely available at all times.
- Acclimation period: At least five days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): The animal room was temperature controlled.
- Photoperiod (hrs dark / hrs light): 12 hour light/dark cycle.

Test system

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

other: 0.9% sodium chloride solution.

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): The test article was dosed by dry weight, 0.5 g/rabbit.

Duration of treatment / exposure:

4 hours.

Observation period:

72 hours.

Number of animals:

6 (3 males and 3 females).

Details on study design:

TEST SITE
- Area of exposure: The prepared site was approximately 10 x 10 cm and remained intact. The test article was placed under a 2.5 x 2.5 cm, moistened 4 ply, surgical gauze patch. The patch was moistened with approximately 1 ml of 0.9% sodium chloride solution to enhance contact of the test article with the dose site.
- Type of wrap if used: Gentle pressure was applied to the gauze to aid in the distribution of the test substance over the prepared site. The patch was
secured with non-irritating tape. The torso was wrapped with plastic in a semi-occlusive manner and secured with non-irritating tape which completely covered the plastic.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Residual test article was removed from the test site by gentle washing with lukewarm tap water at the end of the exposure period.
- Time after start of exposure: 4 hours.

SCORING SYSTEM:
The test sites were scored for dennal irritation at 30 to 60 minutes and 24, 48 and 72 hours after removal of wrappings. Erythema and edema were scored according to the numerical Draize technique below.
The skin was also evaluated for ulceration and necrosis or any evidence of tissue destmction. Additional signs were described.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 24, 48 and 72 hours

Score:

0.11

Max. score:

4

Reversibility:

fully reversible within: 3 days

Remarks on result:

other: Calculated on the basis of the scores at 24, 48, and 72 hours for ALL animals.

Results 2

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 24, 48 and 72 hours

Score:

0.11

Max. score:

4

Reversibility:

fully reversible within: 3 days

Remarks on result:

other: Calculated on the basis of the scores at 24, 48, and 72 hours for ALL animals.

Irritant / corrosive response data:

Erythema and oedema, absent at 30 to 60 minutes after patch removal, were absent to very slight (in one male animal) at 24 and 48 hours and cleared by 72 hours.
There were no abnormal systemic signs noted during the observation period.
Body weight changes were normal.

Other effects:

There were no signs of ill health or toxicity in any animal.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The substance is not classified as a skin irritant.

Executive summary:

Objective:

To determine the potential of the test article to induce dermal imtation when administered demially to New Zealand White rabbits. The study is designed to comply with the standards set forth by:

-EPA - Primary Demnal Initation, 40 CFR 798.4470 (latest revision -1995)

-EC Official Joumal of the European Communities, L 383 A, Part B, Method B.4. Acute Toxicity (Skin Initation) 12/29/92

-OECD Guidelines for Testing of Chemicals, No. 404, Acute Dermal Irritation/Corrosion, adopted 7/17/92.

Method Synopsis:

Six healthy New Zealand White rabbits (3 males-3 females) were dosed dermaily with the test substance. The test article (0.5 g) was applied to one intact site/rabbit. The test article was kept in contact with the skin for 4 hours at which time the wrappings were removed. Dermal reactions were scored at 30 to 60 minutes and 24, 48 and 72 hours after removal of wrappings. Systemic signs were recorded at each observation period. Body weights were recorded pretest.

Summary:

Erythema and edema, absent at 30 to 60 minutes after patch removal, were absent to very slight at 24 and 48 hours and cleared by 72 hours.

There were no abnormal systemic signs noted during the observation period. Body weight changes were normal.

Conclusion:

The test substance is not classified as a skin irritant.